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Finding the Fourth Proportional to 780.99, 1,171.83 and 415.35

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Solution

The fourth proportional to 780.99, 1,171.83 and 415.35 is: 623.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.99 : 1,171.83 = 415.35 : x
  2. Step 2: Convert to fraction form
    780.99/1,171.83 = 415.35/x
  3. Step 3: Cross multiply
    780.99x = 1,171.83 × 415.35
  4. Step 4: Simplify right side
    780.99x = 486,719.59
  5. Step 5: Solve for x
    x = 486,719.59/780.99
  6. Step 6: Final answer
    x = 623.21

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.